SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7dc71f2abde4ec7f14734378653b51b36cf10c8630f463ca17900c0573d2f09f' 
  AND token = '1nCb145gSBEuk2UmF9vvm5dzOFkpSMuYGVBamByqwRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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