SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24fa0bab6077a6dca58275586968356ab88deeb36a3feab86cc5b9453e90f622' 
  AND token = 'FQBOABDU7Sl3M3g3Oa6JDbv7OMmDfR52akYTzmEAxOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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