SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaff6ce0c008deb4db65f7579613e146686a1931d8f6257f8b671aac706262a7' 
  AND token = 'yb0+DDmtqm+9ImrXUUoQ1Iiv5kYswSIghglRlBzQstE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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