SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b17a70016a14b3268cecfcb3411073b02aa63d51304a08f9b1d5045a35ebbf7e' 
  AND token = '6d2iYGB2oPrqGNDBrN3oYPnuHNPsuPX3+c4Nuh30EIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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