SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa1bb2a7781f5592f71e14ed76292f5664e332a98d59572ccaeb49bd79bb382a' 
  AND token = 'lukH+Aix/0DRdBbaRjqCCJIrQZQ4tCxypPVIiCwc8YY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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