SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f489d056a4a97276cbd54898c8372d6b110b721d5cfbcf50f306a1e9ff943c69' 
  AND token = 'omWe+hhKfEn+eNEBs92hRLE2vlezVUqP/7tt0UolwCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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