SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6988cced617ca9d85dfe7827b22da36193ce01828dd8f54976c5379257df5b' 
  AND token = 'dP60Qf+FzFb/vU4yBcbigpGA1q8K5mvEJZRgZ+d4pmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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