SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e59abd77615c8deadc66db535aaf1c279939f12dd6118e2095da7ef9a5d10412' 
  AND token = 'pLUzrU8zR7sPpP9HVW0qJWToqeJJImILhyiellv+TdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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