SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bd5f344279088af2aa5b37b3addbab926986b8cfe5772e804c3d29475b27fea' 
  AND token = 'DbfALVJ/TyTyly/ACL2Yx+aVS5hyYRbg1z2LLSmnPPE=' 
  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"
    }
  }
}