SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78e094b974fc34b82fb397671c4c8a0241197a7a0f1187829e321b2ce9e0c06b' 
  AND token = 'CHnN4QGeSwyLritanJJ1zrrDwfvdJ8bDnl71HwIugr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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