SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a4281698890c6df12c5d1daeaa27cd114bb0f4175735c0b25166de589857dda' 
  AND token = 'muXLYu2g/y5wvvA8Z71Ao1vEM+LPloz3/Z2TBgNdPAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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