SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6f3b29ba7c630c7232039fb8296276dd658e42a53142cee0188e9d184705411' 
  AND token = 'HX/n/09JJYPJ9bI4TT6RYtLu8qbUjshVquNHjgYEqok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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