SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '610b211fdab2a1e95b843a0e70f0e707aed73fba2537652f323eabf127e372d5' 
  AND token = 'SrJViDrlUnMpvGv1Kud+ATRKHQ4gBuCwKbwoM6HmP6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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