SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daebd9d68408e706160dbd277fd5cec4af70b0635f08732af8000557677d89fb' 
  AND token = 'bl0TBa5iWRs1psJFrhYFXOPk+ZPtzhh3Y9i9Xq6T4sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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