SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df26a119ae9ea5504da96c10fd2917ca8bcf7ad05cc2c77bfd636f3c9e997a54' 
  AND token = 'JLTtRGW/5sS28ghcpjqgrFG7H/kXAI36PFNcjpOOzpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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