SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1e1a1c22da377000c113d03b6d63b02e2eaa7fa82fa75c1e269bba17a471e3e' 
  AND token = 'E84XBQnaa/6UPyxU964YDNT/XTvh5R8owTpzKhldK0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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