SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fddb73630cbb4babfb26ef359aca9637c309595cc7471e96a4cec2cfd190fc3c' 
  AND token = 'qJpoiGKBXTnl1J2ZYYeyxIsyZ2GOCVFZgvo6sY5BEws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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