SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea39b43d362f3fbb42b30bfac2af1f07d15baa5646bbaec3f17337e4d7938a01' 
  AND token = 'QryRGlVcqbIPCuqM7cA8wodKmaTxkcc5lYkFNQtR46g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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