SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '98bd032c24b043a812e337d99853d53014e0ec6d34b6255dedc4b8512e1d29de' 
  AND token = 'oCBCE6CuTX3kY7irpQNEp6tn85LdbfMMmBe1W18GO4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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