SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c95192e8a0e4dfac7114078421a8117acb67f5b7f11f39443e4c0d925062876' 
  AND token = 'B5C2aMw3FlpqYUZ+KLFpUsyrPOtf6sCfT08SgfRnyHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}