SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31adca51c3677e4d5d894368848f19992dc436c048f0806371685b789811e637' 
  AND token = 'jVY8AYeWx/4cvw/Q9qM7a+ILmk8jAmJJC1/ox1Kod7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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