SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90fac491fd3dcdad96335a5aa9ffe8e0fbc0850a6634f0a3371861ef6c01fe33' 
  AND token = 'CE+FqCh4TslAIXuM1PVdmS9mVJQzZmgncUUNxEUGctQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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