SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '629d78df4cc4018105fe765ff31e2a0ba4053d43ac17e6cf624fa076ed3be3a6' 
  AND token = 'I37hB4ysR1Uqm31cq67cDj63T1mwIpVbY2Ba7RoFocw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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