SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a8a6361e29817fe140f784bb10c9c4cae17770b1d91c4665751e1735a1cc594' 
  AND token = 'rbMM1OQmOVY2q4WnBl1hOpXXAWDiQnbDLFiKfkJeBac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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