SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69ffe2e3c2b228079a19840901132b8816a185ad76686f98660dd4c97ec27e9' 
  AND token = 'YgzFaW+JR9Sx8svVRgXiCJnpmW3OjX7HFFEhfjg6P+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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