SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42997f9448987c0c858f10fa773530bbfbef77d8828bede5d64831a690cca8a3' 
  AND token = 'qybuXNOxXvaDHH3SEnKpyYPhzDSbGSMF5oliMIK858w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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