SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ca796edbf00f4c7ff1753f796396a8ade2b9804525961a7bf79baf997afb8c' 
  AND token = 'qv62C5VDJFN0FmjZlkUhDMBJ8/W0HzWapemKRIl4V4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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