SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b0f81842a1fdc2ab44695b9375a1d97142dbee61687d4621757e4d98032217d9' 
  AND token = 'Ow2mz+QKfnzkPc9W+qW7bVMDDMxEkXZwublOjFT6Ob4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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