SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c237433899828fcaac290690f72e674adc915ce25e87bb09250410ca121d444' 
  AND token = 'FiDBiwtFNLoqVbj0zItaNeuvD4lZH1AX63v08BD3VmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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