SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f09c20bfa09d7b0fca8e1495cb814c561e12339d665db9c3337f031aa68d62' 
  AND token = 'Zm70IpWFyPwfkafqNN3aVg/wGDeCoCtRw00bnoteMPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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