SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6404a8dcbcee479bf89d07bfda6a716ed9325939e5b2ecaa636bdbbc84c5af9' 
  AND token = 'CmhxlT7nNGT6vUnxLbQGb8ucaedy5yIgW3l8zkXj9k0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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