SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0878bb45a4e3a1f78bcd60942bea7e97f3bb29e9390e61c79b01406425563f' 
  AND token = 'zYYPi6fXprJg+CFJEC9WYG3CiPegjH6FZvL1JXeTSc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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