SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f7508b26db020956e8a273aa46c826c428cd846e412e3e0b179ce6697288d29' 
  AND token = 'PVn79yNQDKbfeyExDPu8Z3SROPBkyAHEflP+dCtRf9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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