SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '82be38b6599d7c287a2bfe3d68041c09b1bff5d422bd62b538f913dea6de1e11' 
  AND token = 'NCElSfddBpIlF52zcguR6r4gt8UqC76Pmqcngs2xer8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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