SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ccdbb2eda3ca0d2d82f7df4f5087b173753d71c790fa4b2cea52da7efadb54' 
  AND token = 'JwcbotbOTzJ4b+GU0NzhkA+WNPioSTGFVHCuxVjxMz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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