SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af5883245616d5b08631305b6a16752f05273bf4d68a249f783c94cf3db4db59' 
  AND token = 'fU7KHWIe0jSoKy4RVYi/FJX44iVJ++9tK1CynfM/1PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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