SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14265ce6c4d4f4a0327793b06bb45c4bbf0bc6eeccbe4cbeb3962b2ea21fa55f' 
  AND token = 'hqMBobTkQ4BPXA9dFlqjrsbTYkyiLdq5a0mYwd3wkyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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