SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3769e699b5269ab9c855608c1f2ba2d479e39dbaa027e384670da79f561bcb1e' 
  AND token = '7AoTGctL4IeSz2t8KgB5qPwdE5z57BdgJL+wiF4wzmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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