SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9980b511c333455d787e45294f28708b422430390d999053bc48ff2f96d25ce1' 
  AND token = 'u9HjIvvGxZpZJHv+737zAVKJekH7BrJwkyn9Esq+MzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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