SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5525846281a14a34608458302618b408b6d72239be065ffd4c7a33d6be79cffa' 
  AND token = 'VNHjfEyzLcYwc+p54xK4TsENopQAhhC3xnoeRVaBmL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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