SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae8b916bb5dcce1f82bb7ca2d098ff4f9eca7e535e08cb7f22e531a43bf770b' 
  AND token = 'buY/fWMRJOtfhU6wilq8FQoHwTrUAenZpm7KBuShzhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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