SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cf2fa3dec5b62eacbdefbc95b3f5d9da9723dd5fce15370fe1f54ee1539707a' 
  AND token = 'oyDKsNgYrrejgYOn/YpiixpSUpkxkVgWKNmtwvOJDnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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