SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89934806b36e93bfa133a5817476a16fb9ea7473ddbd54ae910864f22c4dc138' 
  AND token = 'QhX6pODIA7q+0iQLhEuUf7WwRFiabC4g/pvXWURujJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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