SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6b2e09ad9a95e35fa50099c35ba19881334893c2c5819c220bda640c0a7e1ce' 
  AND token = 'TK0SRyb9UMf/nIGkgIXBMO/sdN0FrndSrkGGTllkUb8=' 
  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"
    }
  }
}