SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1e70826e2b51ea43c181127c87015ceefb03d0aecf45bde86faefdd68fb6792' 
  AND token = 'bv3sxNsaH0ziDtXAzc9/mvvr0jYQc73oT7jUa/w40Vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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