SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04761408d652bd32f857e10e6aafe00dec9988f0646d126065da06d49ba9a774' 
  AND token = 'JYQKRChNrlx9/U+t58D6bR7tnJrsTD54w0+9+YtQmkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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