SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2a0ed9915514788b5b2b2fa8ad8d42abc7f29e9c9dca93565e2a1a8a5baa974' 
  AND token = 'wSWyeODhqSl002wUCsAqPgtAartWVY7k0zdXS3kP8FU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}