SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5800898a8e8da468d279972ae1b68a2dfabbf2c4f4089b4837562da77f6db48' 
  AND token = 'DsvcfSw6IBmcQEFBFJ809KBGZiUJwR2gwqULFnJ1j7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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