SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e88990a5c7d06c28130e1338d9336ad3c0e28fe73edc861788bfd45c9e5dded' 
  AND token = 'rySNHIRAiHem3Ep6WRjxiG4ORhYtXUcTF8Ez0nbiX8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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