SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '183e590f2204c5477500040318e021229136cc70a2162b98b33295887f2c976d' 
  AND token = 'kMPK8O9Jw9vGVqZ95M6IC+zpNApdbxB/Ss2xWHAHxQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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