SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a4168182bcaea4dafcb51a312184f9e57664abb727c4eccc8824077b58efeea' 
  AND token = 'f28QoNaKE+611L37BuS9TfzuzpxUJK8jhHf8t5kklFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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