SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '042595fd433e5689dd3e2230910743795abb37ffe794c27606f4dda555c46e48' 
  AND token = 'MTUvZFNHSXtdvx9PeOkfJz70ZDWAVxmMoX5aLMPFG1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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