SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed662652876b9435d26744748a2d5eaf8bf9771d337321baa98e99c1e2a6e5b7' 
  AND token = 'bh2XIlLwuvrVBakbsVaUXFW5Q2wr5ffk2B0W/nrqETs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}