SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e33b0182e5e2e4f284c7be254500472e84fb5c082e7280692faff672d59daf3e' 
  AND token = 'sed6b+SWwwU4AST6bIWt7HpR6YNlPP6EPxPiDcGRdJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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