SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a88c1f5bf206de637239c9d1bb0a01a3732e6b90b1fe5c7d16c507f0d0f20dab' 
  AND token = '1Fp45dhcFIBCYmepSajzjfn+oVN0xgGlmwETDrYKb4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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