SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1888aace467d49902d6bfbdadd72d019c07307bf5366c1aa9a2ea794c6607aae' 
  AND token = '37dmhZYDewMuYsm5vjlSn0evSYEHNr+GQuguwaVNK1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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