SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6348f10a0c18e0918b827f7d53eca39aa2e8c459bb2a954c6df7f0754949dd61' 
  AND token = 'Bx0zfavgfLQeCMCJnftStBT1WzZAF8lDCKHSfhIezvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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