SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b47825b5263a4e09354ea4172d245d2039ba2a28830e06d249f7029f5d9276cc' 
  AND token = '/KAu94REsF2lC5nM5usuVtWsRgDk1iDsXDEXvSK+Y4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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