SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d97b5d4d73d10a96477260bd73269440843484f895dd72f2250d752bb0b27ff' 
  AND token = 'qDXy+8wGK5C6wSmY8nRz0QwBA6RvhYvInao3LNynDHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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