SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0043755ad00bb8b70c246cda985e7812d0425ef11bf17757fda16125185e4dba' 
  AND token = 'ETCdtU2P+aVAw+OL7ks7jGd74i7C0BVHTEqf3CosyIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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