SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f79d27afb7564746d8a6a86b4036b3bbc3fe6dd14ed7657b46a044c3d9b7ce' 
  AND token = 'LBDgqFQ8JdEhcw/lLbxa5iI4AJnhLsC9BLpmRvd1jHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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