SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '960f66e5b6fb4b33468cfe5540749177d8e7c3e45028fff96e52899cfc5915f0' 
  AND token = 'vcGxHdyQISXEMqZ1TlvVySA1jtdskjdUHLcR7eWy8ik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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