SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe72533c0a574a5e5f07dceb3b4cea69435ceccf86080065407b97c984abd7b' 
  AND token = 'nePMmzlLfqB5D3TOEug98XOtL8Ry0rEyVPYOMfg1LAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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