SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6352c1cd26771f0df93503f03484bd88581da4bc3bd0fbb702155e891795fb' 
  AND token = 'Eesbf301QfxPNPWxzPVV5pps6FGyMoVm6Qq7Qd6gVcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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